Derivative of ln((2x+1)/(x-3))

1. Let $u = \frac{2 x + 1}{x - 3}$.

2. The derivative of $\log{\left(u \right)}$ is $\frac{1}{u}$.

3. Then, apply the chain rule. Multiply by $\frac{d}{d x} \frac{2 x + 1}{x - 3}$:

   1. Apply the quotient rule, which is:

      $$\frac{d}{d x} \frac{f{\left(x \right)}}{g{\left(x \right)}} = \frac{- f{\left(x \right)} \frac{d}{d x} g{\left(x \right)} + g{\left(x \right)} \frac{d}{d x} f{\left(x \right)}}{g^{2}{\left(x \right)}}$$

      $f{\left(x \right)} = 2 x + 1$ and $g{\left(x \right)} = x - 3$.

      To find $\frac{d}{d x} f{\left(x \right)}$:

      1. Differentiate $2 x + 1$ term by term:

         1. The derivative of the constant $1$ is zero.

         2. The derivative of a constant times a function is the constant times the derivative of the function.

            1. Apply the power rule: $x$ goes to $1$

            So, the result is: $2$

         The result is: $2$

      To find $\frac{d}{d x} g{\left(x \right)}$:

      1. Differentiate $x - 3$ term by term:

         1. The derivative of the constant $-3$ is zero.

         2. Apply the power rule: $x$ goes to $1$

         The result is: $1$

      Now plug in to the quotient rule:

      $- \frac{7}{\left(x - 3\right)^{2}}$

   The result of the chain rule is:

   $$- \frac{7 \left(x - 3\right)}{\left(x - 3\right)^{2} \left(2 x + 1\right)}$$

4. Now simplify:

   $$- \frac{7}{\left(x - 3\right) \left(2 x + 1\right)}$$

The answer is: